Container for collection of cultures of parasitic fungi and a method of using the same

ABSTRACT

A container for use in forming a collection of cultures of parasites is made of transparent material, e.g. of transparent plastic, and comprises a vessel having in its upper face an elongated depression of semicylindrical cross-section. A cover enables the vessel to be hermetically sealed by a method eliminating the risk of internal condensation despite the humidity of the agar on which the parasite is cultivated.

ted States Patent 1191 Launey Dec. 23, 1975 CONTAINER FOR COLLECTION OF FOREIGN PATENTS OR APPLICATION CULT OF PA ITIC FUNGI AND A l 462 407 11/1965 France 236/523 METHOD OF USING THE SAME 9471700 l/l964 United Kingdom 21/54 A [76] Inventor: gierrttA. 9, ru des OTHER PUBLICATIONS ane rance Lea et a1. Inactivation of Vacein Virus by Radia- [22] Filed: Oct. 16, 1973 tion, British Journal of Experimental Pathology, 21 Appl. No.: 406,885 I 1942 I Primary Examiner-A. Louis Monacell [30] Foreign Application Priority Data Assistant ExaminerR. B. Penland Oct. 26, 1972 France 72.37979 Attorney, Agent, FirmHaseltine1 Lake & Waters 52 us. c1. 195/54; 195/77; 195/102; [571 ABSTRACT 195/ 139 A container for use in forming a collection of cultures [51] Int. Cl. C12B l/00 of parasites is made of transparent material, e.g. of [58] Field of Search 195/ 101, 127, 139, 54, transparent plastic, and comprises a vessel having in 195/77, I02; 229/25, 43; 220/42 A; 206/84, its upper face an elongated depression of semicylindri- 523; 23/253 TP, 259 cal cross-section. A cover enables the vessel to be hermetically sealed by a method eliminating the risk of [56] References Cited internal condensation despite the humidity of the agar UNTTED STATES PATENTS on which the parasite is cultivated. 2,677,647 5/1954 Lovell 195/139 9 Claims, 3 Drawing Figures US. Patent Dec. 23, 1975 3,928,136

CONTAINER FOR COLLECTION OF CULTURES OF PARASITIC FUNGI AND A METHOD OF USING TI-IE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention f The invention relates to a container permitting the formation of a collection of cultures, interrupted at different stages of evolution, of parasites of a fungal nature. These parasites are those which can be collected from the skin or any other similar surface region of man, animals, and vegetables.

2. Description of the Prior Art Up to the present time it has been known to cultivate such parasites on a suitable medium, generally agar, by known mycological methods inside glass test tubes of the type generally used in laboratories. These cultures are started by the seeding of the medium and, after continuous evolution for a longer or shorter period of time, they are destroyed because it is not possible to preserve them.

It would however by of very great interest to possess stable, durable collections of parasite cultures fixed at various stages of their evolution, and the need for these has been felt for a long time. Such collections, which could serve as reference material, would be very useful to research workers and students, enabling them to compare and identify experimental cultures produced for purposes of medical or pharmaceutical research.

One of the difficulties to be overcome in the formation of such collections is the ability to stop the development of the parasites at the desired stage and to preserve them without alteration for a long period of time.

Another difficulty arises from the fact that mycologists are trained to identify parasites in the'state in which they usually observe them in test tubes, which necessitates a particular thickness and crosssection of the agar serving as support; this results in a mode of development of the parasites, and in certain cases a distribution of colors, which it is advantageous not to disturb in order to enable reliable identification to be made.

SUMMARY OF THE INVENTION The main object of the invention is to provide a container for use in making up a collection of parasites arrested at a particular stage of their growth, which will permit easy observation with a binocular glass. Subsidiary objects are to present the parasites with the usual appearance which they present in test tubes, and to preserve the parasites without alteration despite the fact that the agar serving as support retains a minimum degree of humidity.

According to the invention, a container for the collection of parasites of a fungal nature comprises a vessel having a flat face in which is formedan elongated chamber of semicylindrical'cross;section bounded by transparent material, and a closure cover'adapted to cover the flat face of the vessel and to be hermetically joined to the vessel. I

The elongated chamber may contain agar serving as support for a parasite of a fungal nature which has been arrested in its growth at any desired stage, the cover being sealed to the vessel by a method known per se such as adhesive bonding and welding.

I vide a method of using such containers to form a stabilized collection of parasites with the aid of which, de-

spite the humidity of the agar serving as the support, no condensation capable of hindering observation occurs in the elements. I

According to another aspect of the invention, in a method of using containers as described above to form a collection of parasites of a fungal nature,

the necessary amount of agar is placed in the chamber of the vessel of each container;

a fungal parasite is seeded in the agar and allowed to develop to the desired stage;

the open container is placed in a chamber at 30C for 3 hours;

the container is closed with the aid of its cover in an atmosphere of dry air at 30C;

the cover of the container is sealed; and

the container and the parasite are subjected to a flux of gamma rays from a radioactive source.

According to an alternative aspect of the invention,

form a collection of cultures of parasites of a fungal nature,

the necessary amount of agar is placed in the chamber of the vessel of each container;

a parasitic fungus is seeded in the agar and allowed to develop to the desired stage;

the open container is placed in a chamber at 30C for 3 hours; and

the container is introduced into a chamber containing a sterilizing gas atmosphere, and then the cover is placed in position and hermetically sealed.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a view in perspective of a collection container according to the invention, comprising a vessel and a cover,

FIGS. 2 and 3 are respectively views in longitudinal section and cross-section of the vessel of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION A culture collection container according to the invention comprises a vessel 1 which has an elongated chamber 2 (FIG. 2) having a semicylindrical cross-section (FIG. 3), and which has a flat top face 3.

The elongated semicylindrical chamber 2 is bounded by a transparent material and opens at to the flat fact 3.

The container also comprises a cover 4 adapted to cover the flat face 3 of the vessel 1 and to be joined hermetically to the vessel.

It is advantageous for the vessel 1, as can be seen in FIGS. 1 to 3, to be composed of a wall forming five faces of a hollow parallelepiped, namely a top face (the flat face 3) and four side faces extending from the top face. 1

The elongated chamber 2 is formed by a depression having the abovedescribed section and formed in the top face. This depression extends toa depth which is less than the height of the side walls. Thus, the vessel can stand on the free bottom edge of these walls.

It is preferable for the free bottom edge of the side walls to have an outwardly projecting rim 5 and for the cover to extend as far as this rim. The latter may have a groove 6 intended to receive thebottom edge of the fluid-tight cover, thus facilitating the sealing of the latter to the vessel.

In equivalent manner, the bottom edges of the side walls of the vessel and the bottom edge of the cover may as an alternative be provided with corresponding flanges surrounding the vessel and adapted to be adhesively bonded or welded together by known methods.

The vessel and the cover of each container are made of transparent material, and it is interesting to note that, as will be explained later, it hasbeen found that a plastic material, such as polystyrene, is particularly suitable.

For the purpose of preparing a collection of parasitic fungi with the aid of the containers of the invention, the procedure is as follows.

The necessary amount of agar is placed in the elongated chamber of the vessel.

A parasitic fungus is seeded and allowed to develop to the desired stage, for example until the characteristic appearance of its species is achieved. Its development is then arrested by sterilizing treatment and the cover is sealed on the vessel.

In order to eliminate the risk of internal condensation due to the humidity of the agar, the open contnainer is placed in a chamber at 30C for 3 hours, it is closed by means of its cover in an atmosphere of dry air at 30C and the cover of the container is then sealed.

In order to stabilize it in the state which it has achieved, the parasite is killed by exposing it together with the container to a flux of gamma rays from a radioactive source.

Glass is not suitable for this process, because it is modified by gamma rays; it is therefore preferable to make the container of polystyrene.

Nevertheless, when radioactive material is not available and if glass is used to make the containers it is possible to proceed in the following manner. The operation is as described above until the growth of the parasite is arrested. The container is then placed in a chamber at 30C for 3 hours and it is then introduced into a chamber containing a sterilizing gas atmosphere (ethylene oxide, osmic acid, etc.). The cover is placed in position and hermetically sealed; sealing may advantageously be effected by ultrasonic means.

A container according to the invention which has been prepared in this manner preferably has a utilizable capacity the cross-section of which is that of a semicylinder of a radius of about 9 mm and a length of about 70 mm. Because of this shape, when the container is observed from the side of its curved face the parasite is seen to have a very similar appearance to that usually observed through a test tube. On the other hand, observation through the flat face 3 of the sealed cover makes it possible for a magnifying instrument to be used.

Furthermore, despite the humidity content of the agar, by means of the process for the preparation of these containers, all internal condensation of water vapor, which would hinder obeservation through the walls, is avoided. More specifically, when operating in the mannerjust described, when the agar is at a suitable degree of hydration the vessel is closed in a partially dehydrated atmosphere at the maximum' temperature which the air of a laboratory can attain. In each vessel there is thus achieved equilibrium between the vapor pressure of the water in the agar and the vapor pressure of the air in the vessel. When the outside temperature drops, there is an exchange of water vapor between the air and the agar, without it being possible for the dew point to be acieved, and this is so within a range of temperatures from 15 to 25C approximately.

I claim: I. A containerfor the collection of cultures of parasites of a fungal nature, comprising a vessel and a cover, both constituted of transparent material, said 5 vessel comprising a body having a flat face, said body having an elongated chamber of semicylindrical crosssection which is open at said flat face, said body including opposite side walls, between which the chamber is disposed, said side walls extending from said flat face in the same direction as said chamber and over a distance greater than the depth of the chamber, said cover being constructed to cover the flat face of the vessel and to be hermetically joined to the vessel.

2. A container according to claim I, wherein the elongated chamber contains agar serving as a support for a parasite of a fungal nature which has been arrested in its growth at any desired stage, the cover being hermetically sealed to the vessel.

3. A container according to claim 1, wherein the vessel and its cover are made of polystyrene.

4. A container according to claim 1, wherein the side walls are four in number arranged in opposed pairs which depend from said flat face along four side edges thereof.

5. A container according to claim 4, wherein the side walls of said body include an outwardly projecting rim at the free end thereof remote from the flat face, said cover including side walls adapted for fitting over the side walls of the body of the vessel, said side walls of the cover having free bottom edges which contact said rim when the cover is placed on said flat face to form a hermetically sealed assembly between the cover and said rim.

6. A container according to claim 5, wherein said rim .has a lower flat support surface which is below the level of the chamber to permit the vessel to rest on a surface with the chamber spaced thereabove.

7. A container according to claim 6, wherein said vessel is substantially constituted by a single thickness of said transparent material with the wall of said chamber being suspended from said flat face.

8. A method of using containers according to claim I, to form a collection of parasites of a fungal nature, comprising placing a necessary amount of agar in the chamber of the vessel of each container;

seeding a fungal parasite in the agar and allowing it to develop to the desired stage;

placing the open container in a heated environment at 30C for 3 hours;

closing the container with said cover in an atmosphere of dry air at 30C;

sealing the cover of the container; and

subjecting the container and the parasite to a flux of gamma rays from a radioactive source.

9. A method of using containers according to claim 1, to form a collection of cultures of parasites of a fungal nature, comprising placing a necessary amount of agar in the chamber of the vessel of each container;

seeding a parasitc fungus in the agar and allowing it to develop to the desired stage; placing the open container in a heated environment at 30C for 3 hours; and

introducing the container into a chamber containing a sterilizing gas atmosphere, and then placing the cover in position and hermetically sealing the cover on the vessel. 

1. A CONTAINER FOR THE COLLECTION OF CULTURES OF PARASITES OF A FUNGAL NATURE, COMPRISING A VESSEL AND A COVER, BOTH CONSTITUTED OF TRASPARENT MATERIAL, SAID VESSEL COMPRISING A BODY HAVING A FLAT FACE, WHICH BODY HAVING AN ELONGATED CHAMBER OF SEMICYLINDRICAL CROSS-SECTION WHICH IS OPEN AT SAID FLAT FACE, SAID BODY INCLUDING OPPOSITE SIDE WALLS, BETWEEN WHICH THE CHAMBER IS DISPOSED, SAID SIDE WALLS EXTENDING FROM SAID FLAT FACE IN THE SAME DIRECTION AS SAID CHAMBER AND OVER A DISTANCE GREATER THAN THE DEPTH OF THE CHAMBER, SAID COVER BEING CONSTRUCTED OVER THE FLAT FACE OF THE VESSEL AND TO BE HERMETICALLY JOINTED TO THE VESSEL.
 2. A container according to claim 1, wherein the elongated chamber contains agar serving as a support for a parasite of a fungal nature which has been arrested in its growth at any desired stage, the cover being hermetically sealed to the vessel.
 3. A container according to claim 1, wherein the vessel and its cover arE made of polystyrene.
 4. A container according to claim 1, wherein the side walls are four in number arranged in opposed pairs which depend from said flat face along four side edges thereof.
 5. A container according to claim 4, wherein the side walls of said body include an outwardly projecting rim at the free end thereof remote from the flat face, said cover including side walls adapted for fitting over the side walls of the body of the vessel, said side walls of the cover having free bottom edges which contact said rim when the cover is placed on said flat face to form a hermetically sealed assembly between the cover and said rim.
 6. A container according to claim 5, wherein said rim has a lower flat support surface which is below the level of the chamber to permit the vessel to rest on a surface with the chamber spaced thereabove.
 7. A container according to claim 6, wherein said vessel is substantially constituted by a single thickness of said transparent material with the wall of said chamber being suspended from said flat face.
 8. A METHOD OF USING CONTAINERS ACCORDING TO CLAIM 1, TO FORM A COLLECTION OF PARASITES OF A FUNGAL NATURE, COMPRISING PLACING A NECESSARY AMOUNT OF AGAR IN THE CHAMBER OF THE VESSEL OF EACH CONTAINER; SEEDING A FUNGAL PARASITE IN THE AGAR AND ALLOWING IT TO DEVELOP TO THE DESIRED STAGE; PLACING THE OPEN CONTAINER IN A HEATED ENVIRONMENT AT 30*C FOR 3 HOURS; CLOSING THE CONTAINER WITH SAID COVER IN AN ATMOSPHERE OF DRY AIR AT 30*C; SEALING THE COVER OF THE CONTAINER; AND SUBJECTING THE CONTAINER AND THE PARASITE TO A FLUX OF GAMMA RAYS FROM A RADIOACTIVE SOURCE.
 9. A method of using containers according to claim 1, to form a collection of cultures of parasites of a fungal nature, comprising placing a necessary amount of agar in the chamber of the vessel of each container; seeding a parasitc fungus in the agar and allowing it to develop to the desired stage; placing the open container in a heated environment at 30*C for 3 hours; and introducing the container into a chamber containing a sterilizing gas atmosphere, and then placing the cover in position and hermetically sealing the cover on the vessel. 